Add a fast case to Array.join when all the elements and the separator are fla...

src/ia32/macro-assembler-ia32.h

 // Copyright 2006-2009 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 361 matching lines @@
   // initialized.
   void AllocateConsString(Register result,
                           Register scratch1,
                           Register scratch2,
                           Label* gc_required);
   void AllocateAsciiConsString(Register result,
                                Register scratch1,
                                Register scratch2,
                                Label* gc_required);
 
+  // All registers must be distinct.  Only current_string needs valid contents
+  // on entry.  All registers may be invalid on exit.  result_operand is
+  // unchanged, padding_chars is updated correctly.
+  // The top of new space must contain a sequential ascii string with
+  // padding_chars bytes free in its top word.  The sequential ascii string
+  // current_string is concatenated to it, allocating the necessary amount
+  // of new memory.
+  void AppendStringToTopOfNewSpace(
+      Register current_string,  // Tagged pointer to string to copy.
+      Register current_string_length,
+      Register result_pos,
+      Register scratch,
+      Register new_padding_chars,
+      Operand operand_result,
+      Operand operand_padding_chars,
+      Label* bailout);
+
   // ---------------------------------------------------------------------------
   // Support functions.
 
   // Check if result is zero and op is negative.
   void NegativeZeroTest(Register result, Register op, Label* then_label);
 
   // Check if result is zero and op is negative in code using jump targets.
   void NegativeZeroTest(CodeGenerator* cgen,
                         Register result,
                         Register op,
@@ skipping 306 matching lines @@
   }                                                                       \
   masm->
 #else
 #define ACCESS_MASM(masm) masm->
 #endif
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_IA32_MACRO_ASSEMBLER_IA32_H_